Weather Service Report


327 
FXUS66 KPQR 231652
AFDPQR

AREA FORECAST DISCUSSION 
NATIONAL WEATHER SERVICE PORTLAND 
952 AM PDT SAT MAY 23 2015

.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WAS MOVING SOUTH ALONG THE
COAST AND WILL BE IN CALIFORNIA BY THE AFTERNOON. ANOTHER LOW WAS
CENTERED ALONG THE CENTRAL B.C. COAST AND WILL BE OVER SOUTHERN B.C. 
SUNDAY AND OVER CENTRAL AND EASTERN WASHINGTON MONDAY. THE MAIN 
RESULT WILL BE CONTINUED MODERATE TO STRONG ONSHORE FLOW AND PLENTY 
OF CLOUDS OVER THE AREA...AS WELL AS SOME DRIZZLE OR LIGHT SHOWERS 
MAINLY IN THE LATE NIGHT AND MONDAY HOURS. THE CENTRAL WASHINGTON 
LOW FROM MONDAY WILL MOVE EAST ENOUGH AROUND THE MID WEEK PERIOD TO 
SEE MORE SUNSHINE IN THE AFTERNOON AND EVENING HOURS WITH WARMING 
TEMPS.
&&

.SHORT TERM...WATER VAPOR SATELLITE IMAGERY CLEARLY SHOWED THE SYSTEM
DROPPING SOUTH ALONG THE COAST IS ALREADY MOVING INTO NORTHERN
CALIFORNIA THIS MORNING AND IT WILL BE WELL INTO CALIFORNIA BY THIS
AFTERNOON. IT HAS REINFORCED THE ONSHORE FLOW...WHICH IS MODERATE TO
STRONG AND THUS THE LOW CLOUDS WILL HAVE TROUBLE BREAKING AT ALL
TODAY. THIS SYSTEM HAS ALSO CONTINUED THE EAST TO NORTHEAST FLOW
ALOFT THAT CONTINUES TO SPREAD SOME SHOWERS FROM CENTRAL OREGON INTO
THE CASCADES AND EVEN INTO THE REMAINDER OF THE INLAND AREAS EARLIER
THIS MORNING. THE MODELS INDICATE THAT THE LIGHT ECHOES WILL DECREASE
THROUGH THE AFTERNOON AS THE SYSTEM MOVES SOUTH...THOUGH SOME SHOWERS
MAY STILL BACKDOOR INTO THE HIGH CASCADES THE REMAINDER OF TODAY. AS
A RESULT...TEMPS WILL REMAIN BELOW NORMAL TODAY ACROSS THE FORECAST
AREA.

THERE IS ANOTHER LOW CENTERED ALONG THE CENTRAL B.C. COAST THAT IS
FORECAST TO DROP SOUTH INTO SOUTHERN B.C. LATE TONIGHT AND SUNDAY AND
INTO CENTRAL AND EASTERN WASHINGTON MONDAY. THIS FEATURE WILL ALSO
MAINTAIN/REINFORCE THE ONSHORE FLOW...AS WELL AS FINALLY TURN THE
WINDS ALOFT TO A MORE WEST TO NORTHWESTERLY DIRECTION. THERE IS STILL
A RISK OF SOME PATCHY DRIZZLE AROUND EARLY SUNDAY...BUT WE MAY SEE A
FEW THIN SPOTS IN THE CLOUDS IN THE MID TO LATE AFTERNOON. ON MONDAY
THERE IS A BETTER CHANCE OF SOME DRIZZLE OR SPRINKLES AROUND
ESPECIALLY ALONG THE COAST ON IN THE NORTHERN INLAND AREAS INCLUDING
PORTLAND. THE POSITION OF THE LOW INLAND OVER WASHINGTON ON MONDAY
SUGGESTS THAT CLEARING OF THE MARINE CLOUDS WEST OF THE CASCADES ON
MONDAY MAY BE DIFFICULT AGAIN. BUT THE INCREASED WESTERLY FLOW ALOFT
BOTH SUNDAY AND MONDAY SUGGEST THAT THERE SHOULD NOT BE ANY
THUNDERSTORMS OVER THE AREA. TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MONDAY NIGHT THROUGH FRIDAY...BY MONDAY NIGHT AN UPPER LEVEL LOW
PRESSURE SYSTEM WILL BE SLIDING GENERALLY THROUGH THE REGION...
THOUGH CONFIDENCE IN THE PRECISE TIMING AND TRACK REMAIN RELATIVELY
LOW. MODELS SEEM TO BE CLUSTERING ON A SOLUTION THAT DROPS THE LOW
ALONG OR EAST OF THE CASCADES AS IT MOVES SOUTH FROM CANADA...WHICH
WILL PROVIDE FOR PLENTY OF MARINE CLOUDS BUT KEEP MOST PRECIPITATION
IN THE HIGHER TERRAIN OF THE CASCADES. THEN...SHORTWAVE RIDGING WILL
LIKELY BEGIN TO BUILD OVER THE REGION FOR DRY CONDITIONS AND
WARMING...PARTICULARLY FOR THE SECOND HALF OF THE WEEK. WHILE MODEL
SPREAD REMAINS SOMEWHAT LARGE WITH RESPECT TO HOW HIGH HEIGHTS WILL
RISE...HIGH TEMPERATURES COULD CLIMB INTO THE LOWER 80S FOR THE
INTERIOR ON FRIDAY.  CULLEN 
&&

.AVIATION...CONDITIONS ACROSS THE REGION ARE GENERALLY MVFR WITH CIGS
AROUND 2500 FT AND ISOLATED SHOWERS. INLAND CIGS LOOK TO CONTINUE TO
RISE THROUGH THE MORNING AND SHOULD TURN VFR THIS AFTERNOON/EVENING.
THERE MAY BE SOME BREAKS IN THE CLOUDS TODAY FOR THE INTERIOR
VALLEY...BUT DUE TO A DEEP MARINE LAYER THIS MORNING THERE IS NOT
ENOUGH CONFIDENCE THAT IT WILL DEVELOP. ANY BREAKS THAT DO FORM WILL
LIKELY BE SHORT LIVED WITH INLAND CONDITIONS RETURNING TO MVFR
TONIGHT. THE COAST WILL GENERALLY REMAIN MVFR UNDER WEAK ONSHORE
FLOW...WITH OCCASIONAL PERIODS OF IFR CIGS AND VSBY POSSIBLE THROUGH
SUN. THERE IS AN INCREASING CHANCE THAT IFR CIGS AND VSBY RETURN TO
THE COAST LATE TONIGHT.

KPDX AND APPROACHES...MVFR CIGS WILL GRADUALLY LIFT THROUGH THE
MORNING AND SHOULD TURN VFR AFTER 22Z WITH CIGS AOB 5000 FT. MVFR
CIGS LOOK TO RETURN TONIGHT.
&&

.MARINE...NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION FOLLOWS...
PERSISTENT HIGH PRESSURE OFFSHORE AND LOW PRESSURE INLAND BRINGS
NORTHWEST TO NORTH WINDS ACROSS THE WATERS FOR THE NEXT SEVERAL DAYS.
NOT MUCH CONCERN FOR SPEEDS AS HIGHEST WIND GUSTS STAY SEVERAL KTS
BELOW THE 21 KT CRITERIA. WINDS OFF THE BRITISH COLUMBIA
COAST...HOWEVER...WILL BRING A CHOPPY FRESH SWELL FOR THE NEXT COUPLE
DAYS BEFORE A SLIGHTLY HIGHER AND LONGER PERIOD WNW SWELL DOMINATES
THE WATERS BEGINNING TUESDAY EVENING. /JBONK
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA     
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND

THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON 
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS 
COMMONLY REFERRED TO AS THE FORECAST AREA.

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